RU2209702C2 - Method for making different-thickness sheet products - Google Patents

Abstract

FIELD: plastic metal working, namely manufacture of panels, hatches and other sheet parts with thickened edges while taking into account their lowered strength in zones of thermic influences caused by welding of adjacent parts. SUBSTANCE: method for making different-thickness sheet articles comprises steps of creating shearing deformation in direction of force action upon blank by means of flat strikers in flat sheet constant-thickness blank; simultaneously preliminarily forming flat sheet blank to hollow semifinished product with portion in the form of truncated cone; placing semifinished product into pack between two shaping members having the same height in axial direction, outer diameter D_o and working surfaces (inside pack) engaging with respective surfaces of semifinished product; imparting to mutually opposite surfaces of semifinished products for making round (in plan view) articles form of truncated cones; providing constant total height in axial direction of pack defined by shaping members and semifinished product equal to (0.2 - 0.3)D_o; upsetting prepared pack in container with diameter D_o while transforming initial thickness of semifinished product to thickened portion of article at forming transition thickened zones. EFFECT: prevention of defects of well known similar process for making different-thickness sheets and blanks, enhanced factor of metal usage, lowered labor consumption at working articles. 5 dwg

Description

 The invention relates to the processing of metals by pressure and can be used, for example, in the manufacture of panels, hatches and other sheet metal parts with thickened edges, taking into account their decrease in strength in the heat-affected zone when welding with adjacent parts.

 A technical solution is known for the manufacture of sheet metal products of different thicknesses due to the formation of thickenings on the sheet edges by metal precipitation, for example, with a working roller in a closed cavity between a flat base and a pressure bar using a hydraulic pressure device made in the form of a system of rollers located on both sides of the sheet opposite working roller [1]. The disadvantage of this technical solution is the complexity of the equipment for the implementation of metal precipitation with the presence of independent drives clamping the workpiece, metal precipitation and the need to adjust the power and speed parameters of thickening the edges of the sheets.

 Closest to the proposed invention in terms of technical nature and the achieved effect is a method of manufacturing different thickness sheet products, in which the creation of shear deformations in the workpiece in the direction of force acting on the workpiece provides thicknesses in the sheet, varying 2.0 or more times [2]. However, the marked thickness difference is obtained, firstly, in a hollow sheet product, and not in a flat sheet blank, and, secondly, this difference in thickness is obtained due to thinning of the starting material, and not due to its loss scheniya that significantly limits the ability of the prototype method.

 The technical result achieved by using the invention is to eliminate the noted disadvantages of the prototype in the manufacture of thickness sheets and blanks, to increase the utilization of metal, as well as to reduce the complexity of machining in the manufacture of products.

The achievement of the specified technical result from the use of the developed invention is ensured by the fact that the method of manufacturing different thickness sheet products includes creating shear deformation in the direction of force impact by flat dies in a flat sheet stock of constant thickness, placing it in a bag between two deformable forming elements and settling in a container between flat dies a concomitant change in the initial thickness to the desired thickness of the product, while preliminary th stamping of a flat sheet blank into a hollow semi-finished product with a stamping in the form of a truncated cone, the generatrix of which is inclined at an angle α to its axis according to the dependence:
α = arcsin (S _o / S _y ),
moreover, a small base of a truncated cone with a diameter d is located above a large base with a diameter D at a height H _pf , established by the formula:
H _pf = [(B _y + 2 • B _p ) • cosα-S _o • (1-sinα))] / sinα,
the resulting semifinished product is placed in a bag between two forming elements, the forming elements are axially equal in height with the outer diameter D _o and with the inside package working surfaces in contact with the corresponding surfaces of the semi-finished product, and the opposite surfaces of the latter are shaped in the form of truncated cones with base diameters D and d and a height between them N _pf , and the total height H _Σ in the axial direction of the resulting package of forming elements and a semi-factory that take constant and equal:
H _Σ = (0.2-0.3) • D _o ,
after which the precipitation of the resulting package is carried out in a container with a diameter of D _o , transforming the initial thickness S _{o of the} semi-finished product into a thickened part S _{y of the} product with the formation of transition zones of thickening from S _o to S _y according to the linear law in areas of width B _p according to the formulas:
B _p = R _n • cosα and S _y = S _o / sinα,
where S _o - the initial thickness of the semi-finished product;
S _y is the thickness of the product;
In _p is the width of the transitional thickness zone;
B _y is the width of the thickened part of the product;
H _Σ is the total thickness of the forming elements with the semi-finished product;
N _pf - stamping height in the semi-finished product;
D _about - the diameter of the container, crimping strikers, semi-finished product and forming elements;
D is the diameter of the large base of the truncated cone;
d is the diameter of the small base of the truncated cone;
α is the angle of inclination of the wall of the semi-finished product to the axis of the device;
R _n - the outer radius of the bend of the wall of the semi-finished product.

The invention is illustrated by drawings, which show:
in FIG. 1 is a longitudinal section of a device for thickening the edges of the sheets in the initial position;
figure 2 is the same in position before stamping;
figure 3 is the same in position after stamping;
figure 4 is the same in the position before removing the thickened sheet with forming elements from the device;
figure 5 is a design diagram for determining the parameters of thickening of the sheets.

According to FIG. 1-5, a method of manufacturing a different-thickness products is as follows. First, a sheet blank is stamped in conventional dies or on a turning and pressing machine into an equal-thickness semi-finished product 1 (see Fig. 1) in the form of a cup with a diameter Do, the thickness of which in the flange, bottom and wall parts is the same and equal to the original thickness of the workpiece S _о .

After this, the semifinished product 1 is collected with prefabricated (stamped or cast) forming elements 2 and 3 in a bag with a diameter of D _about and a total thickness of H _Σ and set it on the lower hammer 4, attached to the press table 5. When the press moves, the outer one first goes down press slider 6 with container 7, and then the internal press slider (not shown conditionally) with the upper striker 8 until it contacts the upper form-forming element 2 (see figure 2). Further lowering of the press slider with the upper striker 8 leads to plastic deformation of the forming elements 2 and 3 with the semi-finished product 1 and in the extreme lower position of the upper striker 8 they take the form according to figure 3, as a result of which the forming elements take a flat shape 9 and 10, and the semi-finished product 1 is stamped into a flat product 11, while the flange part 12 and the bottom part 13 of the semi-finished product 1 (being pressed between the flat sections of the forming elements 9 and 10) are practically not deformed. The wall part 14 of the semi-finished product 1, when its flange part 12 is reduced relative to the bottom part 13, is plastically deformed into the thickened part 15 of the product 11 due to shear deformations in the direction of force acting on the plastically deformable bag of forming elements 2 and 3 with the semi-finished product 1 (see Fig. 3). After the manufacture of the product 11 is completed, the outer slider of the press 6 with the container 7 is informed of its movement to its highest position and then the flat hammer is lifted up 8. The deformed forming elements 9 and 10 remaining on the plate 4 together with the stamped product 11 are removed from the press working area: the first for remelting them into new forming elements 2 and 3, and product 11 - for subsequent machining, while low-melting plastically deformable metals, for example, alloy, can serve as metal for forming elements Wood (Т _pl = 60 ^o С), Guthrie alloy (Т _pl = 45 ^o С), Lipovitsa alloy (Т _pl = 70 ^o С), etc. [3]. For the proposed method of manufacturing different-thickness products, the use of low-melting metals with zinc additives according to [4] has a number of technological advantages.

 Firstly, it is cheaper than other alloys, because contains less bismuth, and the expensive component - tin is absent in it.

Secondly, the melting point of this alloy is below 100 ^o C and therefore, to melt this working medium from a stamped bag with the product and for the manufacture of new forming elements, boiling water can be used.

 Thirdly, the content in the low-melting metal according to [4] of zinc at 1.0, 2.0 and 3.0% provides Brinell hardness at 13.9, 15.1 and 17.0 HB, respectively [4], which allows apply this alloy when stamping different thickness products with a wide range of mechanical properties of sheet blanks.

 Thus, for the implementation of the developed method, rigid carriers of product shapes are not required, and therefore, the transformation of an equal-thickness semi-finished product into a different-thickness product is carried out using shear deformations, the direction and size of which are defined by the forming elements 2 and 3 covering the semi-finished product.

With the diameter of the container 7, the upper and lower strikers 8 and 4, as well as the semi-finished product 1 with forming elements 2 and 3 equal to D _o , the total height H _{Σ of the} forming elements 2 and 3 together with the thickness of the flange of the semi-finished product 1 should be taken within
H _Σ = (0.2 ÷ 0.3) • D _o , (1)
since at H _Σ <0.2 • D _o, it is possible to bend the wall sections of the forming elements 2, 3 with the semi-finished product 1 and, as a result, uncontrolled thickening of the product, and at H _Σ > 0.3 • D _{o there} is an inappropriate increase deformation efforts of the package in question.

The calculation scheme in figure 5 allows you to set the appropriate parameters for the implementation of the method of manufacturing different-thickness products from semi-finished products of constant thickness (S _about = const).

Due to the fact that the wall part 14 of the semi-finished product 1 with the initial thickness S _{о is} inclined to the axis of the device (or, which is the same, to the direction of the force acting on the semi-finished product 1) at an angle α, then the wall thickness S of _the semi-finished product in this direction (see . segment "dg") will be:
S _y = dg = S _o / sinα (2).

,
откуда, как и следовало ожидать, при в = 0 имеем толщину в донной части изделия
S_β = S_o•(1+0/tgα = S_o (4)
а при β = 90-α (т.е. в начале образования стеночной части полуфабриката) получаем:

Графоаналитический метод решения уравнения (3) для углов наклона стенки полуфабриката 1 к оси устройства α=30^o, 45^o, 60^o показывает, что переход толщины S_о к S_у и толщины S_у к S_о (см. эпюры S_β = f(β) для α=30^o, 45^o и 60^o на фиг.5) при наружном радиусе скругления стеночной части полуфабриката 1 с его донной и фланцевой частями R_н = S_о (а также и при внутреннем радиусе скругления R_вн = 0) происходит плавно и практически линейно на участках шириной
B_п = S_o•sinβ = S_o•sin(90-α) = S_o•cosα (6)
Для установления геометрических параметров полуфабриката 1 и формообразующих элементов 2 и 3 необходимо определить высоту выштамповки Н_пф в полуфабрикате 1, которая согласно фиг.5 может быть представлена зависимостью:
Н_пф = OA-OB = (B_y+2•B_п)/tgα-(Oo′-S_o)
или, имея в виду, что tgα = sinα/cosα,Oo′ = o′d/sinα = S_o/si α, получаем
Н_пф = [(B_y+2•B_п)•cosα-S_o•(1-sinα)]/sinα (7)
Представленные данные позволяют установить геометрические параметры как исходной листовой заготовки и полуфабриката 1, так и формообразующих элементов 2 и 3 для получения разнотолщинных изделий круглой, прямоугольной и др. формы в плане.The value of the intermediate thickness S _β according to FIG. 5 is written as

,
whence, as expected, at b = 0 we have a thickness in the bottom of the product
S _β = S _o • (1 + 0 / tgα = S _o (4)
and when β = 90-α (i.e., at the beginning of the formation of the wall part of the semi-finished product), we obtain:

The graphoanalytical method for solving equation (3) for the tilt angles of the semifinished product wall 1 to the device axis α = 30 ^o , 45 ^o , 60 ^o shows that the transition of thickness S _о to S _у and thickness S _у to S _о (see diagrams S _β = f (β) for α = 30 ^o , 45 ^o and 60 ^o in Fig. 5) with the outer radius of rounding of the wall part of the semi-finished product 1 with its bottom and flange parts R _n = S _о (as well as with the inner radius of rounding R _int = 0) occurs smoothly and almost linearly in sections of width
B _p = S _o • sinβ = S _o • sin (90-α) = S _o • cosα (6)
To establish the geometric parameters of the semi-finished product 1 and the forming elements 2 and 3, it is necessary to determine the stamping height H _pf in the semi-finished product 1, which according to figure 5 can be represented by the dependence:
H _pf = OA-OB = (B _y + 2 • B _p ) / tgα- (Oo′-S _o )
or, bearing in mind that tgα = sinα / cosα, Oo ′ = o′d / sinα = S _o / si α, we obtain
H _pf = [(B _y + 2 • B _p ) • cosα-S _o • (1-sinα)] / sinα (7)
The data presented make it possible to establish the geometric parameters of both the initial sheet blank and semi-finished product 1, and the forming elements 2 and 3 to obtain different thickness products of round, rectangular and other shapes in plan.

Таким образом ширина зоны утолщения изделия 11 определяется наружным и внутренним диаметрами D= D_н+2•В_п= 200+2•1,73= 203,46 мм и d=Д_вн-2•В_п=180-2•1,73= 176,54 мм (или

), а наружный диаметр полуфабриката 1 (следовательно, и контейнера 7) составляет
Д_о=D+2•В_ф=203,46+2•5=213,46 мм.Consider an example of manufacturing the proposed method of a round hatch in plan with the outer and inner diameters of its thickening D _n = 200 mm and D _int = 180 mm (the width of the thickening V _y = (D _n -D _int ) / 2 = (200-180) / 2 = 10 mm) and the width of the flange In _fl = 5 mm from a sheet of aluminum alloy AMg6M (σ _in = 34 kgf / mm ² ) with a thickness of S _about = 2 mm when it is thickened to S _y = 4 mm (see figure 1, 2 and 5) using for the forming elements 2 and 3 of fusible metal according to [4] with a zinc additive of 1% (σ _vf.e = 7 kgf / mm ² ).
Semi-finished product 1 and the forming elements 2 and 3 in the form of truncated cones according to Fig.1,2 and 5 should have a wall at an angle of inclination α to the axis of the product, the value of which is determined by the formula (2):
sinα = S _o / S _y = 0.5 or α = arcsin0.5 = 30 ^° .
In this case, the width of the transition zone In _p set (when R _n = S _about = 2 mm) according to the formula (6):

Thus, the width of the thickening zone of the product 11 is determined by the outer and inner diameters D = D _n + 2 • V _p = 200 + 2 • 1.73 = 203.46 mm and d = D _vn -2 • V _p = 180-2 • 1 , 73 = 176.54 mm (or

), and the outer diameter of the semi-finished product 1 (therefore, of the container 7) is
D _about = D + 2 • In _f = 203.46 + 2 • 5 = 213.46 mm.

Геометрические параметры изделия 11 почти полностью определяют соответствующие параметры полуфабриката 1 за исключением того, что параллельные линии, определяющие утолщение S_у в листе толщиной S_о, направляют параллельно друг другу, но под углом α к оси симметрии изделия из точек 0'и 0", с последующим сопряжением их с соответствующими линиями в донной и фланцевой частях полуфабриката 11 радиусом R_н=S_о из точек 0' и 0".The height of the stamping in the semi-finished product 1 according to the formula (7) is:

The geometric parameters of the product 11 almost completely determine the corresponding parameters of the semi-finished product 1, except that the parallel lines defining the thickening S _y in the sheet of thickness S _о are directed parallel to each other, but at an angle α to the axis of symmetry of the product from points 0'and 0 ", followed by pairing them with the corresponding lines in the bottom and flange parts of the semi-finished product 11 of radius R _n = S _about from points 0 'and 0 ".

The established parameters of the outer surface of the semi-finished product 1 completely determine the outer and inner surfaces of the upper forming element 2, and the outer surface of the latter should be in the form of a truncated cone with its outer diameter equal to D _about , small and large bases (the diameters of which respectively will be D and d) should stand apart from each other in height at a distance of H _pf , and the corresponding parameters of the inner surface of the forming element 2 are determined by the parameters of the outer surface of the semi-factory that 1 in contact with the forming element 2.

 Similarly, the geometric parameters of the lower forming element 3 are determined according to the corresponding data of the working surfaces of the semi-finished product 1.

To obtain semi-finished product 1 in the form of a truncated cone (according to [5], p.90, formula number 14), the diameter of the workpiece D _in is determined, which is stamped with lead on a metal matrix (according to [5], p.314, Fig. 276), after which form-forming elements 2 and 3 are made from low-melting metal according to [4], they are assembled with the semi-finished product 1 in a bag, which is placed on the lower hammer 4, and during the working stroke of the press, they are deposited with the upper hammer 8 in the container 7. The resulting product 11 is sent for subsequent machining , and the forming elements 9 and 10 for remelting into new elements 2 and 3.

The press force required to implement the proposed method for the manufacture of products with different thicknesses is determined by the area of the container in terms of F _to = π / 4 • D $\genfrac{}{}{0ex}{}{\text{2}}{\text{o}}$ and the tensile strength of the material of the forming elements σ _vf.e = 7 kgf / mm ² i.e.

P _ave = F • O _{to v.f.e.} = 0.785 • 213.5 • 7 = 317688 kgf = 317.7 tf
Thus, according to the above data, both the geometric parameters of the workpiece for stamping the semi-finished product, the semi-finished product itself, the forming elements and the die tooling for the implementation of the proposed method for manufacturing different thickness products, and the power parameters of the equipment for its implementation are set.

 Nonaxisymmetric products of various shapes in plan are similarly manufactured by the considered method.

Sources of information
1. Auth. St. USSR 168863, IPC B 21 D, BI 23, publ. 11/22/1963. Stamp for the formation of thickenings on the edges of the sheets. Sizov E.S. and etc.

 2. Av. St. USSR 1061889, B 21 D 22/20, BI 47, publ. 12/23/83. A method of stamping hollow parts from flat sheet blanks. Sizov E.S.

 3. H.M. Munasipov. Research and development of low-melting alloys and non-metallic compositions for fastening blade blanks during their machining. Appendix to the journal AP 8.

 4. Auth. St. CCCP 1226858. Fusible metal based on bismuth. (Authors: Kh.M. Munasipov, V.K. Doronchenkov, O.A. Moskovsky, Yu.M. Leontyev).

 5. V.P. Romanovsky. Handbook of cold stamping. - L .: Engineering, 1973.

Claims (1)

A method of manufacturing different thickness sheet products, including creating shear deformation in the direction of force by flat dies in a flat sheet stock of constant thickness, placing in a bag between two deformable forming elements and settling in a container between flat dies with a concomitant change in the initial thickness to the required thickness of the product, characterized in that pre-stamping of a flat sheet blank into a hollow prefabricated with stamping in the form of a truncated cone whose generatrix is inclined at an angle α to its axis according to the dependence
α = arcsin (S _o / S _y ),
moreover, a small base of a truncated cone with a diameter d is located above a large base with a diameter D at a height of H _pf , established by the formula
H _pf = [(B _y + 2 • B _p ) • cosα-S _o • (1-sinα))] / sinα,
the resulting semifinished product is placed in a bag between two forming elements, the forming elements are made equally axially with the outer diameter D _o and with the inside package working surfaces in contact with the corresponding surfaces of the semi-finished product, and the opposite surfaces of the latter are shaped in the form of truncated cones with base diameters D and d and a height between them N _pf , and the total height H _Σ in the axial direction of the resulting package of forming elements and a semi-factory that take constant and equal
H _Σ = (0.2-0.3) • D _o ,
after which the precipitation of the resulting package is carried out in a container with a diameter of D _o , transforming the initial thickness S _{o of the} semi-finished product into a thickened part S _{y of the} product with the formation of transition zones of thickening from S _o to S _y according to the linear law in sections of width B _p according to the formulas
B _p = R _n • cosα and S _y = S _o / sinα,
where S _o - the initial thickness of the semi-finished product;
S _y is the thickness of the product;
In _p is the width of the transitional thickness zone;
B _y is the width of the thickened part of the product;
H _Σ is the total thickness of the forming elements with the semi-finished product;
N _pf - stamping height in the semi-finished product;
D _about - the diameter of the container, crimping strikers, semi-finished product and forming elements;
D is the diameter of the large base of the truncated cone;
d is the diameter of the small base of the truncated cone;
α is the angle of inclination of the wall of the semi-finished product to the axis of the device;
r _n - the outer radius of the bend of the wall of the semi-finished product.

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